Raise timeout to RC failsafe

Hi, I am using a 4g LTE connection to send RC and receive video. The connection is stable but as soon as I takeoff, RC failsafe kicks in and drone enters RTL. I discovered that there are milliseconds of RC loss due to latency and other factors, is there any parameter that says for instance “wait for 2 seconds in RC loss before triggering RC failsafe”? RC signal is always there and I never lose it, so it is perfectly safe to pilot the drone. Even after RTL kicks in I can pilot the drone while landing. I would like to raise that timeout to 2-3 seconds and that way I am sure I will never get a failsafe again unless I really disconnect the joystick or I really lose 4g connection, which would be normal cases of failsafe triggering.

It isn’t not currently a user configurable option. The timeout for an RC receiver is 500ms. The timeout using RC Override through the GCS (which I assume is what you’re doing), is 1000ms.

Yeah, then I will have to disable RC failsafe to be able to fly, but that is not the most recommended option, isn’t it?

No, that certainly would not be a good idea and I strongly recommend against disabling it. That would be quite dangerous. 1 second without RC control is quite a long time to begin with. A lot can happen in one second.

If you’re using all automatic modes (auto, guided, rtl) , then the latency isn’t as big a problem unless something catastrophic happens (lose GPS) and you need to take over in manual mode like stabilize or alt-hold. You could increase the FS_RADIO_RC_OVERRIDE_TIMEOUT_MS or disable the RC FS using FS_THR_ENABLE=0 and enable GCS failsafe using FS_GCS_ENABLE=1, which defaults to 5 seconds. You could also slow the copter’s max speeds for loiter, waypoint and descent so that its response is slower to changes in input. Also, eliminate stabilize as an option and only use alt_hold as your manual mode so the copter’s descent can be controlled.

Alternatively, can you prioritize the MAVLink traffic over the video traffic on your LTE connection?

I switched to OpenHD wifi FPV and enabled FS_GCS. Seems OK now :slight_smile: Thank you for your answers and help!